Telephone system



Sept. 8, 1936- R. PFANNSCHMIDT TELEPHONE SYSTEM Filed June 13, 1935 INVENTOR. RUDOLF PFANNSCHMIDT Z Patented Sept. 8, 1936 PATENT orries TELEPHONE SYSTEM RudolfPfannschmidt, Berlin, Germany, assignor to Siemens & Halske Aktiengesellschaft, Wernerwerk Siemensstadt, near: B.erlin, Germany Application June 13,

1935; Serial No; 26,340

In Germany June 21,,1934i 11 Claims.

The present invention relates to a circuit arrangement for characterizing diiferent traflic directions in long distance communication systems, especially telephone systems. In such systemsit line on the part of the preliminary numerical impulse receiver, for example a group'selectontakes up so much time, on account of the different switching operations which must takev place after 10 the setting impulse train has been takenup, that the subsequent setting impulse train arrives before these switching operations are completed. In this way impulses may be suppressed and false calls are caused. This danger is present especially when additional impulses have to be transmitted as criteria for the selection of the different traffic directions.

The present invention'solves the problem ofdecreasing the time taken up by the characterizing line to the shortest duration possible. This is brought about by the arrangement in which depending upon the desired trafiic direction, switching means becomes operative at the outgoing end of the connecting line which effect the characterizing of one traiiic direction by the seizing impulse itself, and the characterizing of further traflic' directions by the interruption of this seizing impulse.

The arrangement according to the invention is applied with advantage in systems in which direct current impulses are transmitted over an inductive path.

The attached figure illustrates an embodiment of the invention. Only those details necessary for understanding the invention are shown.

The connecting line VL, which is electrically isolated by the repeaters Us! and U62 at the outgoing and incoming ends respectively, can be seized according to one of two traffic directions over the leads a, b, c, or a, b, c by a preliminary selector. This is achieved in the known wayby setting the selector on different levels. At the incoming end the traffic direction reachable over leads ai, bl, .cl, corresponds to seizing the connecting line VL at the outgoing end over leads a, b, and c, and at the incoming end of the connecting line the trafiic direction reachable over leads a b 0 corresponds to seizing over leads a, b, c on the part of the preliminary selector,

On seizing the connecting line over the leads a, b, c to which seizure, as already mentioned, the traffic direction at the other end of the line reachable over leads at bl, 0! corresponds to the directed trafiic direction, the seizing relay C energizes may happen that the seizing of the connecting of different traffic directions over a'connecting' at the incoming'end of-the*line,.in the following circuit: earthin the; preliminary selector, wiper c-of the. selector: (not shown) ,test' lead 0, contact Ir, windings of relay'C, battery, earth. Relay C c10ses:its-contacts 2c, 21.0.,150 and. I90. By the closing' of contact 210' the. slow" acting relay E is energized. By the closing of contact I90 relay: V is energized in thefollowing circuit? earth, contact: 21d, winding I of relay V,.contacts 26c, 190, battery; earth: Relay V'is short circuitedthrough contact 260. It thus holds up as a slow acting relay,v after the. energizing of relay E which as contact: 29c breaks the circuit for winding I of relay V,.until.relay Axis energized. On the energizingof' relay C'the. following circuit is completed through' windingl of transformer Tr: earth, contacts.3e,q,2c, winding I of transformer Tr, battery, earth. This circuit is again broken on the" energizing of relayE; Since-thecontacts of relay E are sosadjustedzthat contact He closes before con- 1 tact 3e opens, and. moreover relay V is energized, winding II"v of' transformer Tr thus forms a bridge across the' windings of repeater Uei through contacts I01) and l:le,,and1impulse is induced in windin'g-I'Iiof. transformer Tr and hence also inthe pri- 251* mains in the rest position. This impulse merely serves to magnetizethe repeater Ue l which is still magnetized in a particular direction from the preceding call, so that the transmission of the impulses of a new call can take place without disturbance,

After relays C and E have energized the followingcircuit iscomplet'ed for relay A: earth, contacts I50, l3e, l2d, winding of relay A, battery, earth. Relay A remains energized. until relay D energizes; 222 after the energizing of relay E, but it is constructed as a very slow acting relay so' that' the resting contact l2d remains closed for some time after the energizing of relay E; Thereupon the following circuit is set up over winding I of transformer Tr, after the energizing of relay A: earth, contacts 41/, 511:, winding I of transformer Tr, battery, earth. Through the completion of this circuit another impulse, thesei zil g impulse, is induced in winding II of Relay D is energized over contact transformer Tr and thereby also in the primary winding of repeater Uel. It may be mentioned that relay V is held energized after the energizing of relay A, in the following circuit: earth, contact 2411, winding II of relay V, resistance Wi, battery, earth. The impulse induced in the transformer Tr is transmitted to the polarized impulse receiving relay P of the repeater Ue2 over the connecting line VL.

The direction of this impulse is such that relay P at the incoming end of the line moves its armature over and thereby sets up the following circuit for relay J: earth, contact 59p, winding of relay J, battery, earth. Relay J remains energized so long as the armature of the polarized relay P is held in the work ng position. Relay J completes the following circuit for' relay G: earth, contact 637, winding of relay G, resistance W'iZ, battery, earth. Relay G locks up over its contact 56g independent of relay J. Relay G completes the following circuit for relay H: earth, contact 54g, winding of relay H, battery, earth. Relay H closes the following circuit for relay S: earth, contact 6%, winding of relay S, resistance Wi4, battery, earth. Relay S holds up independent of relay H over contact 59s until relay J releases.

The seizing impulse is brought to an end at the outgoing end of the line VI by the energizing of the slow acting relay D. Through its contact l2d relay D breaks the circuit for relay A. Relay A releases and by opening its contact 5a breaks down the circuit through winding I of transformer Tr. The opening of this circuit results in the renewed induction of an impulse in winding II of transformer Tr. This impulse is transmitted to the polarized relay P over the repeater Uel, the connecting line VL and the repeater Ue2.

The direction of this impulse is such that relay P of repeater Ue2 returns its armature to the rest position and opens contact 56p, but again closes contact Sip. Relay J is thus deenergized. After relay J has deenergized the short circuit of relay K existing over earth, and contacts 45k and 44 is broken, and the following circuit is completed for the latter relay: earth, contact 61g, winding of relay K, resistance Wz'3, battery, earth. After the energizing of relays G, H and K at the incoming end of the connecting line the connecting device or switch attached to leads a l, bl, cl is seized, and then relay energizes over the circuit: earth, contacts 43h, 42k, 39g, winding of relay 0, contact 40m, test lead cl to battery in the attached connecting device. At its contacts 330 and 360 relay 0 switches through the leads al and bl. After the release of relay J relay S releases on account of the short circuit over contact 587'. The repeating of the selecting impulses (setting impulses) in the repeater Ue2 takes place through relay J by the connection of earth to the al or a2 lead through contact 32:1.

The release of the connection takes place by breaking the test circuit incoming over the 6- lead in the selector which is arranged before the line VL. The seizing relay in repeater Uel at the outgoing end of the connecting line VL thereupon deenergizes. Relays E and D then also release. During the time taken by relay D to release, a long releasing impulse is transmitted in the positive direction over the connecting line VL to repeater Ue2 at the incoming end of the line. The negative impulse is suppressed. These switching processes are not illustrated, as not being essential to the invention. At the incoming end of the connecting line VL the long releasing impulse causes a prolonged energizing of relays P, J and S. Relay G is short circuited for a prolonged time over contacts 513 and 557 and thus deenergized. By the release of relay G, relays H and K are also released. After the release of relay'G, relay R is energized in the following circuit: earth, contact 62g, winding of relay R, contact 46s, battery, earth. In a local circuit relay R energizes a second winding of the polarized relay P and thus causes the return of the armature of P to the rest position; this last circuit is not shown. After this release of the armature of relay P, relay J also releases. Relay J short circuits relay S, relay S deenergizes and all the relays of repeater Ue2 are once more in the rest position.

If at the incoming end of the connecting line VL the traffic direction reachable over leads a2, b2, 02 is selected the repeater Uci is seized over the testing lead cl by the pre-arranged selector. Relays X and C thereupon energize in the following circuit: earth in the pre-arranged selector, Wiper c of the selector, testing lead cl, winding of relay X, windings of seizing relay C, battery, earth. Relay C, as already described, effects the successive energization of relays E, V, A and D. After relays C and E have energized an inductive impulse is transmitted over the connecting line VL as also has been described already. This has no effect on the impulse receiving relay P at the incoming end, but merely serves for the corresponding pre-magnetizing of repeater Uel. After relay A has energized a further impulse is transmitted over the connecting line which initiates the seizing. Its direction is opposed to that of the preparing impulse transmitted. An impulse in this direction will be referred to as a positive impulse. After the energizing of relays C and E the following circuit is completed for the slow energizing relay Y: earth, contacts l 50, l3e, Him, I82, winding of relay Y, battery, earth. The energizing of relay Y is delayed to such an extent that it is only energized after relay A, but always before relay D. By opening contact 4;; relay Y breaks down the circuit through winding I of the transformer Tr. Through the opening of this circuit a fresh impulse is induced in the transformer, this time in the negative direction. This impulse reaches the polarized receiving relay P in repeater Ue2 over the line VL and causes the opening of contact 50p and the closing of contact 5| p. In the repeater Ue2 relays P and J have up till now been energized through the positive induced impulse of the seizing impulse, but not relays G and H yet, since the negative induced impulse follows immediately. After the closing of contact 5| p the following circuit is completed in which relay J remains energized, and in addition relay U is energized: earth, contact 5Ip, winding I of relay U, contacts 487', 4171., winding of relay J, battery, earth. Relay U energizes and locks up, independent of relay P, over: earth, contact 4920, winding I of relay U, contacts 487', 41h, winding of relay J, battery, earth. Since relay J remains energized, relay G now also energizes, as already described, in the following circuit: earth, contact 637', winding of relay G, resistance WiZ, battery, earth. Relay G locks up and energizes relay H. Furthermore, the following circuit is now set up, after the energizing of relay G, for the locking winding II of relay U and for relay M: earth, contacts 52g, 53a, winding II of relay U, and parallel to this the winding of relay M, battery, earth. Relay M opens its contacts 34m, 37m, and 40m, and closes its contacts 35m, 38m and Wt.

Thereupon the connection isswitched. over to. the. desired traffic direction. reachable over leads a2,

b2; 02'. After the releaseof. relay J ,relay K. en.- ergizesas already described. The connecting-line 42k, 39g,. winding of relay: 0,. contact. 41m, lead c2, battery in the subsequent connecting. device, earth. In this circuit relay. again energizes. By closing. its two contacts 330 and 3.60. relay 0 switches through the two. speaking IeadsaZ'and 172;.

In the repeater Uel relay Zenergizes in the following circuit after the energizing ofrelay Y: earth,.contacts I50, l3e,. Him, My, winding of relay Z, battery, earth. It'should be mentionedthat.

relay Z energizes before. relay'D. Thus relay. A. still remains energized. of: relay Z the following circuit is again come pleted over winding. I of transformer Tr: earth, contacts 62, a, winding of transformer T1, battery, earth. In the transformer Tr another induction impulse is induced in the positive direction which affects the polarized receiving relay P in the repeater U82 so that contact 51pis opened and contact 50p is closed. Relay J in the repeater Ue2 thus continues to remain energized so as to insure the energizing of relay G and consequently the completion of the seizing.

In repeater Uel relay Z locks up in the following circuit: earth, contacts l5r, 13c, lfix, I'lz, winding of relay Z, battery, earth. Relay Y deenergizes after the opening of contact I82. In the meantime the slow energizing relay D also energizes through contact 226. Relay D by opening contact Zld breaks the circuit for relay A. Relay A releases and breaks the circuit through winding I of transformer Tr by opening its contact 5a. Accordingly an impulse is induced in the transformer, this time in the negative direction. This last subsidiary impulse brings the seizing impulse to an end. In the repeater UeZ the armature of relay P is again switched over by this impulse, contact 50p opens, and contact 55p closes. Relay J releases and by closing contact 513i causes relay S to release.

The release is effected as already described by breaking the testing circuit in the pre-arranged selector, whereby relay C releases in the repeater Uel. A prolonged induced impulse is, transmitted over the connecting line VL in a positive direction, and the negative induced impulse is suppressed. The release in repeater Ue2 takes place as already described. The switching processes for the release are not fundamental to the invention and are therefore not shown.

Having described the invention, what is considered to be new and is desired to be protected by Letters Patent will be set forth in the following claims.

What is claimed is:

1. In a telephone system, a trunk line having two branches, means for producing induced current impulses in said trunk line, switching means 65*111 said trunk line, means responsive to the transmission of a seizing induced impulse in said trunk line for operating said switching means to connect with one of the branches of the trunk line, and means responsive to the interruption of the seizing impulse for connecting with the other one of said branches.

2. In a telephone system, a trunk line having its outgoing end extending in two different traffic directions and in which induced current impulses are produced for seizing and setting the Through the; energizingautomatic switchesinwhich'the traffic directions terminata. switching. means in said trunk line for determining. which of said trafiic directions is to be utilized, means for transmitting an induced impulse to seize said trunk line and operate said switching means tov connect said trunk line with oneof said traflic directions, and means for interrupting: said seizing impulse to operate said switching. mechanism to connect the trunk line Withi the other of said trafiic directions.

3. In a telephone system, a trunk line branched at its outgoing end into two different traiiic directions, switching means in said trunk line for determining which of said branches is to be used, means. for transmitting induced impulses over said trunk line, said switching means operative responsiveto a seizing induced impulse to connect said. trunk. line with one of its outgoing branches and responsive to the interruption of the seizing impulse for connecting the trunk line with the other of saidbranches.

In atelephone system, a trunk line branched atits outgoing end and normally connected to one of the branches, switching means in said trunk line for producing induced impulses, automatic means for seizing said trunk line in one manner and operating said switching means to produce an induced impulse and maintain the connection of the trunk line with the normally connected branch, and automatic means for seizing said trunk line in another manner and operating said switching means to produce a different induced impulse to switch thev connection of the trunk line from the normal to the other branch.

5. In a telephone system, a trunk line having two branches, means for seizing said trunk line, switching means in said trunk line operative responsive to the seizing of the line for extending the trunk line over one of its branches, other switching means in said trunk line operative responsive to the seizure of the trunk line for interrupting said seizing means to extend the trunk line over the other of its branches, said seizing means comprising induced positive and negative impulses.

6. In a telephone system, a trunk line having two branches, means for seizing said trunk line over two different paths, the path over which said trunk is seized determining the branch which is to be used, means in the outgoing end of the said trunk line for transmitting induced impulses thereover, means in the incoming end of the trunk line responsive to the receipt of an induced impulse and depending upon over which path the trunk line is received for extendingthe trunk line over one of its branches in the incoming end of the trunk line if the trunk is seized over the other path for interrupting the induced impulse to extend the trunk line over the other of its branches.

7. In a telephone system as claimed in claim 6, in which the induced impulses comprise positive and negative impulses and in which the impulse transmitting means after interrupting the induced impulse transmits a negative impulse for terminating the seizing of the trunk line.

8. In a telephone system, a trunk line having two branches, means for seizing said trunk line over two separate paths, the path over which the trunk line is seized determining the branch over which it is extended, means in the outgoing end of said trunk line for transmitting induced positive and negative impulses thereover, the seizing of the trunk line over one path being effective to transmit an induced impulse to the incoming end of said trunk line, and means at said incoming end of the trunk line responsive to said induced impulse for selecting the corresponding trunk line branch.

9. In a telephone system as claimed in claim 8, wherein responsive to the induced positive and a negative impulse transmitted over the incoming end of the trunk line to select the required branch, relay means are operated in one manner, while the relay means are operated in another manner in case there is a pause between the positive and negative impulse.

10. In a telephone system, a trunk line having two branches, means whereby said trunk line is seized over two different paths, the path over which said trunk is seized determining the branch which is to be used, means in the outgoing end of said trunk line for transmitting induced impulses thereover responsive to the seizure of said trunk line over either of the paths, means responsive to said induced impulse for selecting one of the branches and responsive to an interruption of the induced impulses for selecting the other branch, automatic switches connected to each of said branches, said switches prepared for operation responsive to the selection of the associated branch and independent of the induced impulse transmitted for selecting the branch.

11. In a telephone system, a trunk line having two branches and an automatic switch in each branch, means for seizing said trunk line over two separate paths, the path over which said trunk line is seized determining the branch which is to be used, means in the outgoing end of said trunk line responsive to its seizure over either path for transmitting induced impulses thereover, a polarized relay in the incoming end of the trunk line responsive to the induced impulses transmitted over the trunk line, and means controlled by said polarized relay and depending upon the character of said induced impulses for selecting the desired branch and preparing the automatic switches thereon for operation.

RUDOLF PFANNSCHMIDT. 

